New techniques for understanding Huntington's disease

A. Transaxial slice of a single-photon emission computed tomography (SPECT) brain perfusion scan from a 23-year-old male with juvenile-onset, genetically proven Huntington’s disease. The patient was placed in a darkened, quiet room, where he received 25 mCi of [Tc]HMPAO intravenously prior to SPECT imaging of the brain. Areas of highest tracer uptake appear white/orange (high blood flow); lowest uptake is blue/black (low blood flow). Note the markedly reduced uptake in the caudate nuclei bilaterally (outlined by white dashed lines). The adjacent thalami are normal. Activity in the cortex is essentially normal in this patient, but it typically becomes abnormal (reduced perfusion) as the disease progresses. High activity in the visual cortex is secondary to visual stimulation the patient received in the partially darkened room. This patient presented with a history of progressive dyskinetic and choreiform movements, hyperkinesia, dysarthria, anger dyscontrol, very inappropriate speech, depressed mood, and episodic crying. The dyskinesias first appeared at age 16.